1. Field of the Invention
The present invention relates generally to a key interlock device and, more particularly, to a key interlock device for preventing removal of an ignition key.
2. Description of Related Art
Generally, for safety reasons, a typical key interlock device is provided in a vehicle so that an ignition key can be removed from an ignition switch only when the shift lever of a transmission is located in the position of Parking (P). The key interlock device is responsible for preventing the removal of the ignition key when the shift lever is located at a position other than the position of ‘P.’
However, when the shift lever is located at a position other than the position of ‘P’ during traveling, the operation of the key interlock device is frequently made, and thus operational noise is generated, with the result that emotional quality is lowered.
Recently, in order to solve this problem, efforts have been actively made to develop devices for reducing such operational noise. As an example of such devices, a key interlock control system is disclosed in Korean Pat. Application. No. 2008-51023.
The key interlock control system receives an ‘IG1’ signal, which is generated when an ignition key is located at the position of an ‘ON’ or ‘START’ terminal, in addition to a ‘P’ signal, thus preventing a key interlock device from operating during traveling. Accordingly, the key interlock control system increases the endurance life of the key interlock device by preventing overheating from occurring due to the continuous flow of current through a solenoid.
However, in the case where the solenoid is located in the vicinity of an ‘ACC’ terminal to block the rotation of a camshaft, as shown in FIG. 1, the ‘IG1’ signal, which is used as a trigger signal for actuating the solenoid, is changed from an ON state to an OFF state. In this case, the angle that is needed to rotate the ignition key to a key interlock block position (the position of the ‘ACC’ terminal), so that the ignition key is returned to the position of a ‘LOCK terminal’ before the rotation of the camshaft is blocked by the solenoid if an ignition key is rather quickly turned. Accordingly, a problem occurs in that the removal of the ignition key may be made even when a shift lever is located at a position other than the position of ‘P’.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.